Protein- and lipid-linked oligosaccharides at the surface of eukaryotic cells are responsible for a wide range of biological processes impacting health and disease. Examples of such processes include fertilization, embryogenesis, neuronal development, hormone activities, the proliferation of cells and their organization into specific tissues. Remarkable changes in cell-surface carbohydrates occur with tumor progression, which appears to be intimately associated with the dreaded state of metastasis. Furthermore, carbohydrates of host cells are often employed by pathogens for cell entry. Not surprisingly, compounds that can interfere in the biosynthesis of oligosaccharides are regarded as attractive leads for drug discovery for wide range of diseases. They also have great potential as agrochemicals, for example as insecticides and fungicides.
Much effort has expended on the development of glycosidase inhibitors, many of which have been isolated from plants and microorganisms. These compounds are often alkaloids whose structures resemble that of monosaccharides. A serious drawback of the use of these alkaloids as drugs is that they inhibit a wide range of glycosidases. Although many analogs of natural glycosidase inhibitors have been synthesized, these efforts have rarely resulted in a selective inhibitor. As a result, only a very small number of glycosidase inhibitors have been successfully developed as therapeutics.